Answer:
The number is 3.
Step-by-step explanation:
To find : A number which decreased by 12 equals 3 times it’s opposite ?
Solution :
Let the number be 'x'.
It's opposite is '-x'.
A number which decreased by 12 equals 3 times it’s opposite
i.e. 
Solving the equation,





Therefore, the number is 3.
Step-by-step explanation:
It is given that the angels of a triangle have a sum of 180°. The angles of a rectangle have a sum of 360°. The angels of a pentagon have a sum of 540.
<u>Let me define the each terms.</u>
1. We know that each angle in a triangle is 60°, So there is a three angle in a regular triangle.
2. We know that each angle in a rectangle, is 90°, So there is a four angle in a regular rectangle.
Similarly,
- There is 8 angle in a regular octagon and each angle measurement is 135°.
So, sum of the angles of an octagon = 135° × 8
Sum of the angles of an octagon = 1080°
Therefore, the required sum of the angles of an octagon is 1080°
<h2>Given :</h2>
<h2>Solution :</h2>

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Richard and Teo are 7 and 24.
7 times two is 14
24 is ten more than 14
31-7 is 24